Things to focus on for mid senior level engineer

Hey folks, I have 3+ yoe in backend development in early stage startup, where mostly I worked on building things from scratch. Wanted your opinions on what all things I should focus on for next phase of my career.

Here is what I want to achieve at the end of next 2 years.

1. Good wlb job with above avg pay(50 lpa) and wfh
2. Want to make my profile and skillset such that I am able to switch job easily if required.